- The Mississippi River: The longest river in North America, the Mississippi flows 3,734 miles from its source at Lake Itasca in Minnesota to the Gulf of Mexico. It drains an area of over 1.2 million square miles.
- The Missouri River: The longest tributary of the Mississippi River, the Missouri flows 2,341 miles from its source in the Rocky Mountains in Montana to its confluence with the Mississippi River near St. Louis.
- The Ohio River: The largest tributary of the Mississippi River by volume, the Ohio flows 981 miles from its source at the confluence of the Allegheny and Monongahela rivers in Pittsburgh to its confluence with the Mississippi River near Cairo, Illinois.
- The Colorado River: The Colorado River flows 1,450 miles from its source in the Rocky Mountains in Colorado to the Gulf of California. It drains an area of over 246,000 square miles.
- The Columbia River: The Columbia River flows 1,243 miles from its source in the Rocky Mountains in British Columbia to the Pacific Ocean. It drains an area of over 259,000 square miles.
- The Yukon River: The Yukon River flows 1,980 miles from its source in the Rocky Mountains in British Columbia to the Bering Sea. It drains an area of over 320,000 square miles.
